The characteristic performance of an electronic circuit is typically described by a set of performance specifications. Within a given set of performance specifications may be characteristics of many different dimensions. Each dimension may relate to a different domain in which a circuit may be analyzed. Basic electrical specifications, such as those having dimensions of volts or amperes, may be analyzed in the DC domain of circuit operation. Specifications that relate to the time domain response of a circuit may be referred to as transient characteristics. Circuit characteristics, such as those that describe response as a function of signal repetition rate, may be analyzed in the frequency domain.
In addition to multiple analysis domains, each performance specification may be measured as a function of multiple sets of operating conditions. Some typical operating condition variables include circuit temperature, supply voltage, and fabrication process.
In order to synthesize a circuit that is suitable for a given application, it is desirable to optimize performance for all circuit characteristics in each analysis domain, preferably under multiple operating conditions. In one approach to circuit optimization, a circuit simulation program is used to perform each of the individual analyses required to measure performance. Each analysis domain then requires a separate simulation. In another approach, a sequential process is used to perform the required analyses in a serial manner. The time required to complete the analyses is the total sum of each individual analysis time. This approach does not lend itself to efficient, automated optimization, due to the time required to collect results of each iteration and to execute new iterations with each new set of optimization variables.
It is therefore an object of the present invention to develop a process for synthesizing a circuit that utilizes a minimal total analysis time.
It is also an object of the present invention to develop an improved process for optimizing performance objectives in circuit synthesis.